--  @testpoint:opengauss关键字absolute(非保留)，作为函数名
--关键字不带引号-成功
drop function if exists absolute;
create function absolute(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function absolute;

--关键字带双引号-成功
drop function if exists "absolute";
create function "absolute"(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function "absolute";

--关键字带单引号-合理报错
drop function if exists 'absolute';
create function 'absolute'(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/

--关键字带反引号-合理报错
drop function if exists `absolute`;
create function `absolute`(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/